Tata Motors — TATA NEXON AMT gearbox oil leakage in 6 month old car

I purchased TATA NEXON AMT in May 2021 and drove 1700 KM only. It started giving ioil leakage from engine side. When checked at authorised service center they told gear box has leakage and they will replace with new. After leaving car for 12 days at service center they are telling they don't have new gearbox to replace and no idea when will it be fixed.

Looks like they gave and old gearbox to me with cost of new.

I as car buyer am quite frustrated and helpless with service from Tata.